Model-Based Software for Configuring Switch Scanning Systems The overall goal of this work is to improve outcomes for people who use switch scanning. Switch scanning is used by individuals with severe motor and speech impairments as a method for entering text and data into computers and augmentative communication devices. The text entry rate (TER) with scanning can be less than one word per minute, but adjusting the configuration settings in the system can dramatically affect communication rate [4,5,27]. The challenge is identifying the most appropriate scanning settings to match the unique needs of each individual user. We propose to develop software that allows practitioners and scanning users to identify highly effective settings for a scanning system. The software, called Scanning Wizard, will help practitioners choose the right configuration options and configure those options to maximize TER for the user. In Phase II we will complete the following tasks: 1. Design and implement the software, using an iterative user-centered approach, resulting in a fully functional beta-level application that will run on multiple platform. 2. Evaluate its utility and usability in a protocol simulating actual use of the product. 3. Expand and refine the software. Based on user input during Tasks 1 and 2, as well as bench testing of technical quality, we will expand and refine the beta version into a more robust and complete product. 4. Evaluate the efficacy of Scanning Wizard in a field study involving a variety of practitioners and scanning users. The Scanning Wizard software will be the first of its kind to guide practitioner-user teams through the process of establishing effective settings for a switch scanning system. Given Phase I results demonstrating average rate enhancements of 120%, use of this tool will provide dramatically improved outcomes for people who rely on scanning for their communication and computer access.